1. Turn off User Records mode.
2. Go to the Stadium Select Screen.
3. Scroll all the way to the right
(Houston will be on the top left).
4. Click on Houston, and contiunue clicking diagonally downand to the right (Houston-top left, middle stadium, bottom right stadium)
5. Now click in a line diagonally up and to the right, bottom left, middle stadium, top right stadium)
6. If done right you will hear TRIPLE PLAY. Scroll to the right and you will have 3 new stadiums.